Buffers Plus
Richard W. Ramette Northfield, MN 55057
Note:	This program is included in both the General Chemistry Collection (SP-16) and the Advanced Chemistry Collection (SP-28). To Order General Chemistry Collection To Order Advanced Chemistry Collection
In 1989 JCE Software published The Acid-Base Package: A Collection of Useful Programs for Proton Transfer Systems (1). This DOS program has been fully upgraded by the same author to the world of Windows 95. Buffers Plus takes advantage of a modern user interface and offers many new options not possible in the original version. The opening screen (Figure 1) offers seven options that cover a wide variety of needs for students learning about theory, practical pH calculations, titration curves, buffer preparation, buffer capacity, ionic strength effects on equilibria, alpha curves, etc. A particularly useful feature is the use of scroll bars for dynamic views of how key parameters influence titration curves, buffer capacity, and alpha plots. Figure 1. Buffers Plus presents seven options for study of acid-base equilibria. The seven Buffers Plus options are: A. A tutorial on the subjects of buffer algebra, alpha plots, ionic strength, activity coefficients, reference buffers, titration curves, buffer types, and buffer capacity. B. Calculates the equilibrium pH values from a specified initial composition chosen from a wide variety of acid-The base mixtures. C. Demonstrates the effects of typical approximations of water ionization and acid dissociation, as well as ionic strength, on calculated pH and composition values. D. Calculates how a specific buffer could be prepared in the laboratory given the desired values of buffer pH and ionic strength, as well as pKa values. E. Explores graphically how the buffer capacity of mono-, di-, and triprotic systems, and also the related alpha values, vary with solution pH. F. Plots titration curves for acid-base and base-acid titrations, with options for showing the effects of ionic strength, alpha values, buffer capacity, and more. The pertinent pK value(s) are controlled by scroll bars, and the plotted curves change dynamically to show the pK dependence (Figure 2). A zoom feature applies to the endpoint regions. G. Presents typical problems to solve using Buffers Plus in areas of pH calculations, buffer recipes, titration curves, buffer capacity, and alpha values. Users may easily jump to and from any of the options, in any order. Figure 2. Titration curve of triprotic acid with buffer capacity. The plots are updated automatically as parameters are adjusted using the sliders. Buffers Plus is intended for individual exploration by students, as a basis for assignments by the instructor, and for projecting illustrations in the classroom. Hardware and Software Requirements Computer: Windows compatible CPU: 80486 or higher RAM: 16 MB or greater Drives: Hard drive, High-density (1.44 MB) floppy drive Graphics: 640 x 480, 256 colors System: Windows 95/98 This program will not run under Windows 3.1 Literature Cited Ramette, R. W. J. Chem. Educ. Software 1989, 2B No. 2. Availability Available: Now

First Published: November 1998

Citation: Ramette, R. W. Buffers Plus J. Chem. Educ. Software 989803

Keywords: Lecture Aid; Computer Room; Simulation; High School; General; Alpha plots; Buffers; Calculations and plotting of data; Titration curves

News | Issues | CD-ROM / Video | Find It! | Technical Support | For Authors
JCE Online | Journal | Software | Internet | Happenings | About JCE | Contact JCE
Last Updated: July 19, 2001 Created: November 11, 1998	Created by: N. S. Gettys Comments to: jceonline@chem.wisc.edu
© 1997 Division of Chemical Education, Inc., American Chemical Society. All rights reserved.